Evaporating apparatus



Nov, 23 1943., c. F. ROSENBLAD 2,334,95fi

EVAPORAT ING APPARATUS Filed Aug. 14, 1940 2 Sheets-Sheet l imyw BY r M mkY Nov. 23, 1943.

C. F. ROSENBLAD EVAPORATING APPARATUS Filed Aug. 14, 1940 2 Sheets-Sheet 2 VEETOR f lower' ends of the tubes of the group I and the upper ends ofthe'tubes of the group lb; and finally the lower ends of group lb terminate in a lowercompartment Ca below that group at the bottom of the apparatus. In this way the two groups of tubes are? connected in seriesso that the inside tubular surfaces receive liquid de-. liveredat the upper ends of the tubes from the respective compartment C1 or C: located next opening l2. For distributing the liquid in proper manner to the inside tubular surfaces, the heating tubesare provided with nozzle like inlet devices 2 fitted to the upper endswf. the tubes through which the tubes communicate with the respective compartments C1 or Cz'located next above, on the bottom of which there is main-.

tained a pool of liquid of suflicient depth for the liquid to be delivered by these" inlet devices to the tubes. Further, the heating tubes are provided with discharge means 3a or 3b at the lower ends within the respective compartment C2 or C3 located next below, which discharge means are designed to provide separate escape of the liquid and vapor generated therefrom; from the tube passages into such a lower compartment so that the liquid will be collected at the bottom of these compartments whereas the vapor will flow'into the upper portions thereof.- The vapor received in the compartmentsCz and C3 are removed therefrom in parallel by the pipe system As shown, the upper group of heating tubes la may suitably consist of agreater number of tubes than'=the lower group lb and the tubes may be either conical in shape with the crosssectionalarea decreasing downwards in the directions of flow; as in the group Ia, or cylindrical as in the group I b. By using such conical tubes or by the group arrangement disclosed with the number of tubes'dec'reasing through successive groups from an upper group to a lower one inthe direction of flow, the total tubular surface receiving the liquid is diminished asthe quantity of liquid is diminished by evaporation so that preferably of a nozzle like construction, as more clearly shown in Figs. 2 through 5, and consist of hollow pieces fitted tothe upper ends of the tubes in the fashion of a plug. Thus the device has a cylindrical portion introduced into the tube passage in tight contact with the tube wall and has a top portion projecting above the tube end.

. The topof the'inlet device is closed by aremovable cover plate-20 and in the projecting top portion there is provided one or more lateral entrance ports 2| directed tangentially into a vertical cylindrical. bore 22 in that portion, which bore at the bottom communicates with a conically widening orifice =23 'opening from the cylindrical portion downwardly into the tube. The liquid enters through ports 2| into the upper bore 22 with a certain velocity in tangential direction and iscaused by the centrifugal forces to be spread in the form of a film over the conical surface defining the orifice 23 from the lower edge of which surface the film passes on to the thermore a turbulent flow of the liquid is effected tube wall to flow down along the same by gravity. Thereby, a very smooth and easily controllable distribution of the liquid to the tube walls as a perfectly uniform film is attained, while furby virtue of'the centrifugal action of the device.

Insuchhevices the upper bore 2l and the ori doc 23 can either be concentrically disposed, as in Figs; 2 through 4, and in that case the device should have at least two entrance ports 2| at diametrically opposite places in order to obtain a strong centrifugal action, or the bore 22 and the orifice can be eccentric as at 23a in the modification according to Fig. 5, in which case a single entrance port 2| may be sufficient.

Naturally. however, there may also be used other liquid distributing means in combination with the other inventive features.

the quantity of the liquid passing per unit of surface is maintained approximately constant throughout the apparatus, and thus a high efiiciency issecured.

Another novel feature is that the upper ends of the heating tubesproject above the tube. plates in the respective compartments to such a height that the portion of the tube to which the liquid,-

liquid is delivered is located within that compartment so that the liquid is delivered at a level 1 above the heating zone of the tubes in order to prevent any evaporation in or adjacent tothe inlet devices of the tubes for-reasons already stated.

flangesor collar 5a or For the same purpose-it may be suitable to sur- Returning again to the discharge means 3c and 3b for the heating tubes according to the invention it will be recognized that the different medi fications shown are of the same general type, and in actual practice of course only one or the other is used in the same apparatus.

As shown in Figs. 6 and 7, and 8 and 9, respectively, the discharge means 3a or 3b consistsof a comparatively short tube piece of equal diameter with the heating tube. This tube piece is removably attached to the heating tubes la or lb at thelower end thereof by means of a suit able connection deviceX or Y,,as a flow conducting tube extension located within the compartmentCz or C3 below the heating tube. In the tube, piece, the lower end of which is open, thereare provided one or more lateral outlet openings 4a or 4b for vapor, these lateral openings having-preferably the shape .of longitudinal slots. or 4b ,hasfth'e periphery, vertical edge portions thereof, surrounded by a V 5b or the like projecting radially inwards into the tubular passage. These. collars 5a or 5b havesuitably a streamlined shape viewed in the direction of flow within the tubular passage and serve as guiding surfaces for the liquid fiow,...so that thefilm'of liquid on theinside tubular surface is broken up at points just above the lateral openings to or 41) so that the liquid flow is deflected around the openings. This prevents the liquid from either flowing through the lateral openings 4a or 42) or formin a veil across the same, and consequently the vapor may escape separately through said unrestricted openings, without mingling with the Further, each of the lateral openings;

at least the upper nonliquid, whereas the liquid leaves separately at the lower open ends to or 8b. Hence the vapor enters means, as shown by Figs. 8 and 9, the tube extension has only a slngle'lateral outlet opening 4b cutting off aportion of the tube periphery from and including a portion of the lower edge thereof so that there the lateral opening lb merges into axial lower opening 6b, and in this more simple construction the lateral opening lb is provided with a flange or collar 52) which need surround only the upper curved or inclined periphery of the opening and which may suitably be welded to the edge thereof.

Of course, it is not necessary that such discharge means should include removable extension pieces although this is the most practical, but it is also possible to make similar tube extensions integral with the heating tubes, by welding, for instance, or instead the heating tubes themselves-may have the end portions formed as discharge means.

Further, it is' understood that the discharge means for the heating tubes may be changed'in various ways not here disclosed and that there may be used entirely different discharge means in connection withthe diverse inventive features described above.

In conclusion, it shall be emphasized that the scope of the invention is not limited otherwise than by the appended claims.

What I claim is:

1. In an evaporating apparatus, a vertically arranged heating tube, means for heating the exterior of said tube, liquid distributing means disposed at the upper end of said tube for supplying liquid to be evaporated in a film to the interior surface of the tube, the lower portion of said tube being formed with a lateral opening for the discharge therethrough of vapor, and means within said tube presenting guiding surface for diverting the liquid film away from said opening, whereby the vapor is discharged through said opening without mingling with the liquid.

'2. In an evaporating apparatus, a vertically arranged heating tube, means for heating the exterior of said tube, liquid distributing means disposed at the upper efld of said tube for supplying liquid to be evaporated in a film to the interior surface of the tube, the lower portion of said tube being formed with a lateral opening for the discharge therethrough of vapor, and a flange extending inwardly from the wall of said tube around at least the upper edges of said opening to divert the liquid film away from the opening, whereby the vapor is discharged through said opening without mingling with the liquid.

3. In an evaporating apparatus, a vertically arranged heatingtube, meansfor heating the exterior of said tube, liquid, distributing means disposed at the upper end of said tube for sup-,

plying liquid to be evaporated in a film to the interior surface of the tube, a hollow member removably connected to the lower end of said tube, said member being formed with a lateral opening for the discharge therethrough of vapor,

and means within said member presenting guid-.

ing surface for diverting the liquid film away from said opening, whereby the vapor is discharged through the opening without mingling with the liquid.

4. In an evaporating apparatus, a vertically arranged heating tube, means for supplying heat to the exterior of said tube, a nozzle member disposed at theupper end oi the tube and having a tangentially disposed inlet port, means for supplying liquid to be evaporated to said port, said nozzle having a conical orifice extending into said tube, the smaller end of said orifice communicating with said tangential port and the extending into and contacting the upper end of said tube and having an orifice for supplying larger end substantially coinciding with the inner wall of said tube, whereby liquid is spread in a film over the surface of said orifice from where the film flows onto the inner surface of the tube, and means for collecting liquid and vapor discharged from the lower end of said tube.

5. In an evaporating apparatus, a vertically arranged heating tube, means for heating the exterior of said tube, a liquid distributing nozzle liquid to be evaporated in a film to the interior surface of said tube, at least the portion of said nozzle in which the orifice is formed being anade of material having 'a low coemcient of heat conductivity, and means for collecting liquid and vapor discharged from the lower end of said tube.

6. In an evaporating apparatus, means including a bottom wall forming an inlet chamber for liquid to be evaporated, means for supplying liquid to said chamber, a vertically arranged heating tube extending through said wall, means for heating the exterior of a portion of said tube below said wall, a liquid distributing nozzle located in said chamber and extending into the portion of said tube which is above said wall for supplying a film of liquid to the interior surface of said tube, the liquid in said chamber serving to maintain said nozzle and the upper portion of said tube at a temperature below the boiling point of the liquid, and means for collecting liquid and vapor discharged from the lower end of said tube.

7. In an evaporating apparatus, a vertically arranged heating tube, means for heating the exterior of said tube, a liquid distributing nozzle extending into the upper end of said tube and having an orifice for supplying liquid to be evaporated in a film to the interior surface of said tube, heat insulating material disposed around the upper portion of said tube into which the nozzle extends, and means for collecting liquid and vapor discharged from the lower end of said tube.

CURT ROSENBLAD. 

